battery question

[cospilot]

first off let me point out that i have a very extensive background in electronics. so i don't need the detailed reply for this question.
but i see a lot of people talk about battery banks that consist of 2 6 volt batteries wired in series.
i realize that in this configuration that each 6 volt battery probably has about 2x the storage of a 12 volt of the same case size.
but what is the benefit of 2 6 volt batteries of 200 reserve amps in series verses 2 12 volt batteries of 100 amps each reserve in parallel?
don't you end up with the same thing?

i ask because my 32BHPR has room enough for 2 batteries i believe on the tongue behind the propane. it only came with 1 battery. if i was to add a second battery of 12 volts or perhaps if there was room for 3 and add a 3rd wouldn't i have more capacity if i have room for 3 verses 6 volts i can only do in pairs thus limiting me to just a pair of 6 volt in series.

[JRTJH]

The available amperage is essentially comparable. Where the difference comes into play is the available reserve at "deeper discharge" levels and the ability of the "golf cart" batteries to be recharged more times from a deeper discharge level. In other words, you can get pretty much the same "dry camping capacity" from either the two 6 volt batteries in series or the two 12 volt batteries in parallel.

The "rub" comes in how long they will last with repeated "deep discharges" and how well they hold up to the rigors of dry camping with that "heavy electrical demand upon departure": namely, pulling in the slides on the way home......

Putting a high amperage demand on an "almost depleted" 12 volt battery (alone or in parallel with another) with the much thinner plates they are built with, becomes the "killer" for the 12 volt battery bank. Discharging at that level repeatedly will cause them to fail much sooner than a similar 6 volt system because of the battery construction.

[SLIMSHADIE]

What he said

Also 1 bad 12 volt will ruin the other, so adding another 1 years later prob is not a good idea. They both should be new. Typically 6 volts dont do that to each other, but if 1 goes bad

My 12 volt went bad after 4 years, so i opted to do the 2 6 volts. I had a dual battery tray, so why not. If i remember correctly the 2 6 volts would of been equal to 3 12 volt batteries, in amp hours, if I had bought the same replacement

[dave-g]

After looking a lot I found that the 6 volt battery has more room between the plates- this makes them last longer under deep discharge.

[Bluewater]

Check out the AGM batteries and all the benefits they offer over both the others. I've had them for over a year now and can really see a difference when dry camping.

[cospilot]

thanks for the replies!

i don't think i will do much dry camping, but my trailer sits in an RV lot. i have been considering installing a solar panel to keep it topped up and on occasion without concern turn on the refrigerator a day or 2 beforehand to get it down to temp.
i would like to know i have a fresh battery in cases like that.

additionally i have toyed with the idea of having extra storage should i decide to dry camp because i may want to run a 110 volt inverter for watching tv or running small things for short periods of time without the worry of running out.

i suppose i can just bring a generator. my father in law has a pair of honda 2000i gens that he never uses.

but i am OCD about my stuff, to a degree i like to have the extra storage and the ability to drycamp despite the fact i may not really ever do that.
i do know 1 location i am likely to dry camp for a couple days riding dirt bikes in taylor park. but maybe between having my truck handy to recharge the batteries in a pinch or a generator to provide the AC power for microwave may solve my temporary need for the short term.

i think for my needs i may just get another 12 volt like the one i have, get a solar panel or 2 installed to keep them topped up.

[srvnt]

I have 2 golf cart batteries but bring a spare 12v for longer dry trips in case one 6er should fail. never had to use it, but its insurance. On dry trips that last more than a week, since I don't use a genny, I also bring my 2 12s that came with the trailer.

[dave-g]

"but i am OCD about my stuff, to a degree "

I'm right there with you-
I wanted to get the solar for when the rv is in storage- but use a Honda 3000 gen when I dry camp.

When we go to motorcycle races for the weekend- I start the gen when we arrive and shut it down when we leave- may run for 2 days straight. When we beach camp at Assateague Island, I'll run the gen for 2 hours a day to keep every thing topped off. But run off a single 12v other wise.